Endothelial damage occurs early after inhalation injury as measured by increased syndecan-1 levels.

Inhalation injury is a significant cause of morbidity and mortality in the burn patient population. However, the pathogenesis of inhalation injury and its potential involvement in burn shock is not well understood. Preclinical studies have shown endothelial injury, as measured by syndecan-1 (SDC-1) levels, to be involved in the increased vascular permeability seen in shock states. Furthermore, the lung has been identified as a site of significant SDC-1 shedding. Here we aim to characterize the contribution of endotheliopathy caused by inhalation alone in a swine model. When comparing injured animals, the fold change of circulating SDC-1 levels from preinjury was significantly higher at 2, 4, and 6 hours postinjury (P = .0045, P = .0017, and P < .001, respectively). When comparing control animals, the fold change of SDC-1 from preinjury was not significant at any timepoint. When comparing injured animals versus controls, the fold change of SDC-1 injured animals was significantly greater at 2, 4, 6, and 18 hours (P = .004, P = .03, P < .001, and P = .03, respectively). Histological sections showed higher lung injury severity compared to control uninjured lungs (0.56 vs 0.38, P < .001). This novel animal model shows significant increases in SDC-1 levels that provide evidence for the connection between smoke inhalation injury and endothelial injury. Further understanding of the mechanisms underlying inhalation injury and its contribution to shock physiology may aid in development of early, more targeted therapies.

Role of Submandibular Ultrasound in Airway Management of a Patient With Angioedema.

Angioedema is one of several life-threatening clinical scenarios that lacks clarity on when a patient requires intubation. We present a case of angiotensin-converting enzyme-inhibitor-induced angioedema with peri-oral swelling and normal airway measurements on ultrasound, who was intubated with an abundance of caution and extubated successfully. Current tests for intubation and extubation, such as traditional bedside assessments and the cuff leak test, vary in reliability for angioedema and similar urgent situations. Submandibular ultrasound is a quick, low-cost, non-invasive method for determining quantitative criteria for and assessing when intubation and extubation is indicated, which may lead to improved quality of care and patient safety.

A Pilot Study of Negative Pressure Therapy with Autologous Skin Cell Suspensions in a Porcine Model.

BACKGROUND: Negative pressure wound therapy (NPWT) is an option for securing meshed split thickness skin grafts (mSTSGs) after burn excision to optimize skin graft adherence. Recently, the use of autologous skin cell suspension (ASCS) has been approved for use in the treatment of burn injuries in conjunction with mSTSGs.To date, limited data exists regarding the impact of NPWT on healing outcomes when the cellular suspension is utilized. It was hypothesized that NPWT would not negatively impact wound healing of ASCS+mSTSG. MATERIALS AND METHODS: A burn, excision, mSTSG, ASCS ± NPWT model was used. Two Duroc pigs were utilized in this experiment, each with 2 sets of paired burns. Four wounds received mSTSG+ASCS+NPWT through post-operative day 3, and 4 wounds received mSTSG+ACSC+ traditional ASCS dressings. Cellular viability was characterized prior to spraying. Percent re-epithelialization, graft-adherence, pigmentation, elasticity, and blood perfusion and blood vessel density were assessed at multiple time points through 2 weeks. RESULTS: All wounds healed within 14 days with minimal scar pathology and no significant differences in percent re-epithelialization between NPWT, and non-NPWT wounds were observed. Additionally, no differences were detected for pigmentation, perfusion, or blood vessel density. NPWT treated wounds had less graft loss and improved elasticity, with elasticity being statistically different. CONCLUSIONS: These data suggest the positive attributes of the cellular suspension delivered are retained following the application of negative pressure. Re-epithelialization, revascularization, and repigmentation are not adversely impacted. The use of NPWT may be considered as an option when using ASCS with mSTSGs for the treatment of full-thickness burns.

A comparison of the extent of resection in pineal region tumours via the occipital transtentorial and supracerebellar infratentorial approaches.

PURPOSE: To perform a single unit review of surgical approaches to the pineal region, looking to ascertain if trends were identifiable regarding the extent of resection and the rate of post-operative complications between approaches. We hypothesised that each approach would offer different exposure of the pineal region which may result in poor access to certain areas of the tumour. This may lead to residual tumour in reliable and predictable locations, and an awareness of these regions could help with pre-operative planning and lead to higher levels of suspicion when inspecting these regions intraoperatively. MATERIALS AND METHODS: We performed a single centre, retrospective review of all adult and paediatric patients who underwent surgical debulking of pineal region tumours between 2008 and 2019. Patient demographics, pre- and post- operative radiological tumour volume data, histology and complication rates were compared between the two groups. RESULTS AND CONCLUSIONS: The occipital transtentorial approach resulted in a significantly lower extent of resection when compared to the supracerebellar infratentorial approach (p = 0.04), even after multivariate analysis (p = 0.006). There was no significant difference between the location of residual tumour relative to the superior colliculi between the two approaches (p = 1.00). There was a significant incidence of radiological occipital lobe ischaemia from the occipital transtentorial approach (p = 0.04). Within our series, we did not demonstrate a consistent location of residual tumour relative to the surgical approach chosen. Whilst there was a significant difference with regards to the extent of resection between approaches, in the context of small comparative groups this is difficult to draw far-reaching conclusions from.

Institutional Experience Using a Treatment Algorithm for Electrical Injury.

Electrical injury has low incidence but is associated with high morbidity and mortality. Variability in diagnosis and management among clinicians can lead to unnecessary testing. This study examines the utility of an electrical injury treatment algorithm by comparing the incidence of testing done on a cohort of patients before and after implementation. Demographics, injury characteristics, and treatment information were collected for patients arriving to a regional burn center with the diagnosis of electrical injury from January 2013 to September 2018. Results were compared for patients admitted before and after the implementation of an electrical injury treatment algorithm in July 2015. There were 56 patients in the pre-algorithm cohort and 38 in the post-algorithm cohort who were of similar demographics. The proportion of creatine kinase (82% vs 47%, P < .0006), troponin (79% vs 34%, P < .0001), and urinary myoglobin (80% vs 45%, P < .0007) testing in the pre-algorithm cohort was significantly higher compared to post-algorithm cohort. There were more days of telemetry monitoring (median [IQR], 1 [1-5] vs 1 [1-1] days, P = .009) and greater ICU length of stays (4 [1-5] vs 1 [1-1] days, P = .009), prior to algorithm implementation. There were no significant differences in total hospital lengths of stay, incidence of ICU admissions, in-hospital mortality, or 30-day readmissions. This study demonstrates an electrical injury evaluation and treatment algorithm suggests a mode of triage to cardiac monitoring and hospital admission where necessary. Use of this algorithm allowed for reduction in testing and health care costs without increasing mortality or readmission rates.

Bacterial Virulence Factors and Their Contribution to Pathophysiology after Thermal Injury.

Background: Bacterial infections are the leading cause of morbidity and mortality in burn-injured patients. Pseudomonas aeruginosa and Staphylococcus aureus are among the most common pathogens responsible for infections in thermally injured patients. These and other pathogens have developed a variety of virulence factors to colonize and infect hosts. Methods: A comprehensive literature review was conducted to best summarize the current knowledge of how virulence factors contribute to bacterial pathogenicity. Results: The review highlights the unique mechanisms bacteria utilize to evade host defense systems and further complicate the treatment of burn-injured patients. Conclusion: Further research on virulence factors and their contribution to bacterial pathogenicity is warranted and could potentially lead to development of neutralizing pharmacotherapy that would complement antimicrobial treatment.

Pulse Oximetry Is Unreliable in Patients on Veno-Venous Extracorporeal Membrane Oxygenation Caused by Unrecognized Carboxyhemoglobinemia.

Continuous bedside pulse oximetry (SpO2) is universally used to monitor oxygenation for patients supported on veno-venous extracorporeal membrane oxygenation (VV-ECMO). Yet, elevated carboxyhemoglobin (COHb), a known event in VV-ECMO, diminishes the reliability of SpO2. This retrospective cohort study aims to assess the accuracy of SpO2 compared with oxyhemoglobin (SaO2) and quantify COHb levels by co-oximetry in the VV-ECMO population. Forty patients on VV_ECMO from 2012 to 2017 underwent 1,119 simultaneous SaO2 and SpO2 measurements. Most patients were male (60%) with average age of 46 years. SpO2 overestimated SaO2 values by 2.35% at time of cannulation and 0.0061% for each additional hour on VV-ECMO (p < 0.0001). Twenty-nine (72.5%) patients developed elevated COHb (>3% of hemoglobin saturation) at least once during VV-ECMO support and 602 (40.2%) arterial blood gases yielded elevated COHb levels. Mean duration for ECMO with elevated COHb was 244 hours compared with 98 hours in patients without (p < 0.0048). Patients who developed COHb were younger (mean age 40 vs. 55 years, p < 0.024) and had single-site double-lumen cannulation (odds ratio = 4.5, p = 0.23). At time of cannulation, mean COHb was 2.18% and increased by 0.0054% for each additional hour (p < 0.0001). For every 1% increase in COHb, SaO2 decreased by 1.1% (p < 0.0001). During VV-ECMO, SpO2 often overestimates SaO2 by substantial margins. This is attributable to rising COHb levels proportional to duration on VV-ECMO. In this population where adequate oxygen delivery is often marginal, clinicians should be wary of the reliability of continuous pulse oximetry to assess oxygenation.

Pro-Con Perspectives on Ethics in Surgical Research: Update from the 39th Annual Surgical Infection Society Meeting.

Background: Surgical research is potentially invasive, high-risk, and costly. Research that advances medical dogma must justify both its ends and its means. Although ethical questions do not always have simple answers, it is critically important for the clinician, researcher, and patient to approach these dilemmas and surgical research in a thoughtful, conscientious manner. Methods: We present four ethical issues in surgical research and discuss the opposing viewpoints. These topics were presented and discussed at the 39th Annual Meeting of the Surgical Infection Society as pro-con debates. The presenters of each opinion developed a succinct summary of their respective reviews for this publication. Results: The key subjects for these pro-con debates were: (1) Should patients be enrolled for time-sensitive surgical infection research using an opt-out or an opt-in strategy? (2) Should patients who are being enrolled in a randomized controlled trial (RCT) comparing surgery with a non-operative intervention pay the costs of their treatment arm? (3) Should the scientific community embrace open access journals as the future of scientific publishing? (4) Should the majority of funding go to clinical or basic science research? Important points were illustrated in each of the pro-con presentations and illustrated the difficulties that are facing the performance and payment of infection research in the future. Conclusions: Surgical research is ethically complex, with conflicting demands between individual patients, society, and healthcare economics. At present, there are no clear answers to these and the many other ethical issues facing research in the future. Answers will only come from continued robust dialogue among all stakeholders in surgical research.

Further Histological and Cellular Characterization of Hidradenitis Suppurativa in 11 Patients.

Background: Hidradenitis suppurativa is a chronic inflammatory skin disease, with significant morbidity secondary to its recurrent painful and exudative lesions. Given limited research on the cytoarchitecture of hidradenitis suppurativa, this study describes the microscopic structure and cell surface markers present in hidradenitis suppurativa tissue to better understand the disease and identify potential therapeutic targets. Methods: Skin biopsies of hidradenitis suppurativa lesions from patients who underwent surgical excision (n = 11) were compared with grossly normal-appearing perilesional skin (n = 5) and normal skin biopsies from unaffected individuals (n = 4). Histopathology and epidermal thickness were assessed using hematoxylin and eosin and picrosirius red staining, and CD3, a T-cell marker, and CD31 (PECAM), a vascular endothelial cell marker, were assayed using immunofluorescence. Data were analyzed and compared using analysis of variance and Student's t test. Results: Histological examination showed that hidradenitis suppurativa samples had a significantly thicker epidermal layer than normal skin (335.23 ± 165.01 µm vs 57.24 ± 18.43 µm, P = .005), extending into and engulfing the dermis. The hidradenitis suppurativa dermis had extensive cellular infiltration and aggregation as well as disorganized collagen. Immunofluorescence analysis revealed that, at the dermal level, hidradenitis suppurativa lesions had a significantly greater quantity of CD3+ (324.29 ± 139.28 vs 14.93 ±16.32, P < .0001) and CD31+ (322.15 ± 155.46 vs 2.84 ± 5.56, P < .0001) cells/mm2 compared with normal skin samples. Conclusions: Hidradenitis suppurativa lesions have thicker epidermal layers, more dermal cellular infiltrate, and disorganized collagen fibers compared with normal skin. Furthermore, hidradenitis suppurativa dermis has a greater quantity of CD3+ and CD31+ cells than normal skin.

Extensive hidradenitis suppurativa with dorsal foot involvement: a case report.

Hidradenitis suppurativa (HS) is a highly morbid chronic inflammatory skin disease resulting in painful and purulent lesions classically occurring in areas with a high density of apocrine glands such as the groin and axillae. This is the case of a 53-year-old male with medically refractory Hurley stage III HS affecting multiple anatomical sites including the dorsum of the right foot, an atypical location. Throughout his hospital course, he underwent a series of surgical excision and graft procedures to treat extensive HS lesions on various anatomical locations. In patients with a history of HS, mechanical stress may result in atypical lesion locations. In addition to the standard medical and surgical treatment, management should include optimizing nutritional parameters, smoking cessation, wound care and reducing friction and pressure at the affected area.

Colo-Pro: a pilot randomised controlled trial to compare standard bolus-dosed cefuroxime prophylaxis to bolus-continuous infusion-dosed cefuroxime prophylaxis for the prevention of infections after colorectal surgery.

Standard bolus-dosed antibiotic prophylaxis may not inhibit growth of antibiotic resistant colonic bacteria, a cause of SSIs after colorectal surgery. An alternative strategy is continuous administration of antibiotic throughout surgery, maintaining concentrations of antibiotics that inhibit growth of resistant bacteria. This study is a pilot comparing bolus-continuous infusion with bolus-dosed cefuroxime prophylaxis in colorectal surgery. This is a pilot randomised controlled trial in which participants received cefuroxime bolus-infusion (intervention arm) targeting free serum cefuroxime concentrations of 64 mg/L, or 1.5 g cefuroxime as a bolus dose four-hourly (standard arm). Patients in both arms received metronidazole (500 mg intravenously). Eligible participants were adults undergoing colorectal surgery expected to last for over 2 h. Results were analysed on an intention-to-treat basis. The study was successfully piloted, with 46% (90/196) of eligible patients recruited and 89% (80/90) of participants completing all components of the protocol. A trialled bolus-continuous dosing regimen was successful in maintaining free serum cefuroxime concentrations of 64 mg/L. No serious adverse reactions were identified. Rates of SSIs (superficial and deep SSIs) were lower in the intervention arm than the standard treatment arm (24% (10/42) vs. 30% (13/43)), as were infection within 30 days of operation (41% (17/43) vs 51% (22/43)) and urinary tract infections (2% (1/42) vs. 9% (4/43)). These infection rates can be used to power future clinical trials. This study demonstrates the feasibility of cefuroxime bolus-continuous infusion of antibiotic prophylaxis trials, and provides safety data for infusions targeting free serum cefuroxime concentrations of 64 mg/L. Trial registration: NCT02445859 .

The Impact of Advancing Age on Recurrence and Survival Following Major Hepatectomy for Colorectal Liver Metastases.

INTRODUCTION: This study analysed the effect of age on survival in patients undergoing major hepatectomy (MH) for colorectal liver metastases (CRLM). The effect of adjuvant chemotherapy (AC) with age was also assessed. METHOD: Patients undergoing MH for CRLM between 1996 and 2011 were reviewed. Patients aged <75 or ≥75 were compared for disease-free (DFS) and overall survival (OS) as well as impact of AC on survival. RESULTS: Seven hundred twenty-seven patients underwent MH of which 105 (14 %) were aged ≥75. Morbidity was greater in the ≥75 group (25 versus 34 %, p = 0.048). No difference was noted in mortality. There was no difference in DFS between the two groups at 5 years (16.8 vs 18.9 months (p = 0.570). OS was longer in the <75 group (38.6 vs 32.0 months (p = 0.001). DFS was better in groups receiving AC than those not (<75 24.2 vs 12.2 months (p = <0.001) and ≥75 24 vs 12.1 months (p = 0.007)). OS in the ≥75 group was improved in the group receiving AC compared to the ≥75 group not (41.1 vs 16.6 months, p = 0.005). Age ≥75 was not an independent risk factor for reduced DFS on multivariate analysis. CONCLUSION: Well-selected patients aged ≥75 should be considered for MH followed by adjuvant chemotherapy.

Patterned assembly of genetically modified viral nanotemplates via nucleic acid hybridization.

The patterning of nanoparticles represents a significant obstacle in the assembly of nanoscale materials and devices. In this report, cysteine residues were genetically engineered onto the virion surface of tobacco mosaic virus (TMV), providing attachment sites for fluorescent markers. To pattern these viruses, labeled virions were partially disassembled to expose 5' end RNA sequences and hybridized to virus-specific probe DNA linked to electrodeposited chitosan. Electron microscopy and RNAase treatments confirmed the patterned assembly of the virus templates onto the chitosan surface. These findings demonstrate that TMV nanotemplates can be dimensionally assembled via nucleic acid hybridization.